#include <iostream>
#include <cstring>

int main()
{
    // void* ptr = NULL;
    // void* ptr = 0;
    // void* ptr = nullptr;

    int var = 8;
    //double* ptr = (double*)&var;
    int* ptr = &var;
    *ptr = 10;
    std::cout << var << std::endl;

    char* buffer = new char[8];
    memset(buffer, 0, 8);

    char** dptr = &buffer;

    delete[] buffer;
    //very important to release the memory or it will cause memory leak.
}